1. Article: What are Biosensors?
Biological sensor is made up of a transducer and a biological element that may be an enzyme, an antibody or a nucleic acid. The bioelement interacts with the analyte being tested and the biological response is converted into an electrical signal by the transducer. Depending on their particular application, biosensors are also known as immunosensors, optrodes, resonant mirrors, chemical canaries, biochips, glucometers and biocomputers.
A commonly cited definition of a biosensor is:
“A chemical sensing device in which a biologically derived recognition is coupled to a transducer, to allow the quantitative development of some complex biochemical parameter.”
Every biosensor comprises:
- A biological component that acts as the sensor
- An electronic component that detects and transmits the signal
2. Diagram from Rapid Detection of Food Adulterants and Contaminants: Theory and Practice By Shyam Narayan Jha
3. Article: Application of Biosensors in the food industry.
- Enzyme biosensors based on the inhibition of cholinesterase enzymes are used to detect traces of organophosphates and carbamates from pesticides that may be present as poisonous and harmful residues on farm produce.
- Some microbial sensors are selective and sensitive in the detection of ammonia and methane.
- Biological oxygen demand (BOD) analyzers use a bacteria such as Rhodococcus erythropolis immobilized in collagen or polyacrylamide. These devices are widely used to test the quality of waste water. BOD biosensors can analyze 2 to 20 samples every hour.
- Biosensors may be used to measure carbohydrates, alcohols, and acids in fermented foods. The devices are mainly used for quality control processes in food production. The devices, however, need to be kept sterile, frequently calibrated and require analyte dilution. Enzyme-based biosensors can be used in food quality control to measure amino acids, amides, amines, carbohydrates, heterocyclic compounds, carboxylic acids, gases, inorganic ions, cofactors, alcohols and phenols. Biosensors can also be used in the assessment and analysis of produce such as wine, beer and yoghurt.
- In food quality assessment, antibodies or immunosensors may be used in assays to detect small molecules such as water-soluble vitamins and chemical contaminants. They may also be used to detect any pathogenic organisms present in meat, poultry, eggs, and fish.
4. BOOK : Food Biosensors | edited by Minhaz Uddin Ahmed, Mohammed Zourob, Eiichi Tamiya
Terminology : Point of Care technologies (POC). For example, SciO is an optical POC technology. Electronic tongue for liquid sample and Electronic noses for gas.
2.3.2 Food Biosensing in Developing regions.
Use paper due to its low cost, high surface area, biocompatibility, flexibility, disposability, small volume of reagents required for analysis,
Colorimetric paper-based devices: Spot test (static) and lateral/vertical flow (dynamic)
The possibility of creating hydrophilic patterns ( using wax printing,e.g) enables the fabrication of several test zones for different analytes in the same device, which increase the reliability of this tool
RFID biosensors : inductive-capacitive (LC) antenna circuit that reacts to an interrogative signal emitted by a detection coil and send back a resonant frequency signal dependent on the capacitances and inductance of the sensor
Biosensing systems are becoming more portable and user-friendly. In our opinion, this trend will continue, and smaller, less expensive devices able to perform multicomponent analysis will reach the market
5. Article: Novel Biosensors could detect food contaminants by Joe Withworth
ORLA : Multi-channel SAW Biosensor for multiple diagnoses
There is a need for rapid, simple and low-cost point of care tests for respiratory viruses. Our technology enables SAW technology to be used to its full potential with biological samples and the resulting devices are able to detect disease antigens in samples from serum, urine, or saliva. The biochips translate antibody-antigen binding events from samples into an electronic signal, successfully combining rapid disease diagnosis with inbuilt wireless connectivity.
Researchers from Stratophase, a firm out of Southampton, United Kingdom, just published a paper in journal Biosensors and Bioelectronics, describing the technology inside their SpectroSens chip, a new optical micro device designed to rapidly detect pathogens and biochemicals. The chip can be loaded into a robust device to simultaneously identify 16 different potential health threats like anthrax and ricin toxin.
INTEGRATED PRINTED BIOSENSOR PLATFORMS
There is a need for robust disposable sensor systems that are easy to use and manufacture. Application areas could be point of care, food safety, environmental monitoring and agriculture.